Gap fairing for a tractor-trailer

ABSTRACT

A gap fairing for a tractor-trailer is provided. A fairing body with an impact absorbing extension is attached to a chassis of the tractor, independently of the cab thereof and within a gap between a cab of the tractor and the trailer. The fairing body has side portions, extending rearwardly from a front portion, adjacent the cab of the tractor, toward the trailer and top portion. A clear panel can be located in at least the side portion of the fairing body located at the passenger side to enable the driver to view the trailer through the rear window of the tractor and the clear panel. A separation space between the front of the fairing body and the cab can be sealed by a sealing element that is at least in part one of resilient and flexible so as to allow relative motion between the fairing body and the cab.

RELATED APPLICATIONS

This application is a continuation-in-part of, and claims priority from,U.S. patent application Ser. No. 13/938,661 filed Jul. 10, 2013 which isa continuation-in-part application of U.S. patent application Ser. No.13/561,829 filed Jul. 30, 2012.

FIELD OF THE INVENTION

The present invention relates to a gap fairing for a tractor-trailer inwhich the gap fairing is mounted in a gap between the tractor and thetrailer to reduce aerodynamic drag induced by cross winds that wouldotherwise enter the gap and to increase streamlining of air flow from acab of the tractor to the trailer. More particularly, the presentinvention relates to such a gap fairing with a body portion and a impactabsorbing extension in which the body portion of the gap fairing ismounted to the chassis of the tractor independently of the cab, and theimpact absorbing extension is a rearward extending structure thatprotects the body portion from impact by the trailer during maneuveringof the tractor-trailer.

BACKGROUND

Tractor-trailers are used for over the road transport of goods and otherproducts. Typically, the trailer is pivotably connected to the tractorso that the combination can be maneuvered and with a spacing or “gap”between the tractor cab and the trailer. This gap is a particular sourceof drag for all tractor-trailers of all cross sectional shapes,including cylindrical tankers such as are used in the industrial gasbulk distribution business, the oil industry and etc.

Aerodynamic drag is a major contributor to fuel consumption, especiallyat speeds above 50 MPH. Aerodynamic improvements can contribute to fuelsavings and provide cost reduction. Fuel consumption reduction alsogreatly enhances carbon footprint reduction and helps meet additionalenvironmental quality standards and objectives. The gap described aboveadversely and significantly affects fuel economy. As will be discussed,reducing the size of this gap results in a reduction in fuel consumptionof about seven percent.

Tractor-trailers in which a tank is mounted on the trailer are aparticular type of bluff body vehicle known to have high dragcoefficients. Aerodynamic drag in the gap area is known to be a functionof the sub-optimal flow transition from the size and shape of thetractor cab and that of the trailer. The tanker trailer often has afrontal area with air impingement not otherwise deflected by the tractorcab. Also, with the nearly inevitable presence of side wind vectors, theenlarged gap due to the configuration of the tanker trailers allowsentry of cross winds and associated forces which also act on the frontalface of the trailer. This resulting flow separation further contributesto increased aerodynamic drag and increased fuel consumption.

Where tractor-trailers are used for transport of liquefied atmosphericgases, these tankers often depart an air separation plant with themaximum over-the-road limited weight. This necessitates adjustments tothe effective wheelbase for load distribution among the axles. Thisrequired redistribution of the weight tends to require furtherlengthening of the gap which in turn, additionally increases theaerodynamic drag in that spatial arrangement.

The reduction of drag by enclosing the gap between tractor and trailerwith a gap fairing has been recognized in the prior art. In this regard,an example of a current commercially available gap fairing is describedin U.S. Pat. No. 3,834,752 which discloses a gap fairing that is sizedfor the common range of gap distances, from the back plane of thetractor cab to the front plane and arc of swing of the box or vantrailers, where the gap distance is markedly shorter than on fullyloaded tanker trailers. More recently a gap fairing on an industrial gasbulk liquid delivery tanker has been introduced. This tractor included a“cab-over configuration”, still typically used in the United Kingdom andEurope but obsolete in the United States. The gap fairing for thisrecent design does not include an extended back portion required tooptimally achieve maximum gap coverage. The gap fairing is attached tothe tractor cab, resulting in the transmission of intended and possiblyunintended loads into the very thin tractor cab surface necessitatingsupplemental structural enhancement. This particular fairing designwould require significant modification, tooling, and fitting changes foruse with a multitude of tractor sizes, shapes and materials ofconstruction variability.

US Patent Application No. 2011/0109121 discloses a gap fairing that canbe used in connection with tractor-trailers having a tank that addressesthe size and shape transition, from rectangular cab to cylindricaltrailer, as well as consideration of the necessary spacing fortractor-trailer articulation during backing maneuvers. The fairingconfiguration attaches to the tractor cab, with the attendant impositionof loads on the cab surface and/or structure. This idealized shape,however, has been found by the inventors to represent a costlymanufacturing challenge. In addition, the highly conformalfairing-to-cab interface would require significant changes to the designand tooling for a range of tractors with sizes, shapes or materials ofconstruction variations.

A problem common to all fairings that are located behind the tractorcab, is that they block visibility to the passenger side of the tractor.This can be a problem during maneuvering of the tractor trailer,particularly when the tractor trailer is being backed into a facility.The reason for this is that the driver's view of the trailer,particularly when the trailer is angled toward the tractor at thepassenger side is blocked by the fairing.

As will be discussed the present invention provides a gap fairing for atractor-trailer and the use of such a gap fairing in reducing drag.Among other advantages of a gap fairing in accordance with the presentinvention is that such gap fairing is attached directly to the tractorchassis independently of the cab, can be easily adapted for a variety oftractor-trailer designs and can be fabricated in a less expensive mannerthan gap fairings of the prior art and further, is provided with a clearpanel to facilitate maneuvering of the tractor trailer.

SUMMARY OF THE INVENTION

The present invention may be characterized as a gap fairing for reducingaerodynamic drag of a tractor-trailer having a tractor and a trailerpivotably connected to the tractor. The gap fairing comprises a fairingbody attached to a chassis of the tractor within the gap between a cabof said tractor and a trailer of said tractor-trailer and configured toenable the trailer to pivot during maneuvering of the tractor-trailer.The fairing body has a front portion, a top portion, side portions andone or more impact absorbing extensions extending rearwardly from theside portions of the fairing body.

The one or more impact absorbing extensions extending rearwardly fromthe side portions of the fairing body protect the fairing body and thetrailer from any impact between the fairing body and the trailer duringmaneuvering of the tractor-trailer. The impact absorbing extensions andthe side portions are configured to inhibit cross-winds from enteringthe gap and streamline air flow from sides of the cab to the trailer.The impact absorbing extensions are preferably constructed from aflexible, compressible or resilient type material, such as anelastomeric material, that provides a physical barrier between the sideportion of the fairing body and the trailer. In some embodiments of thepresent gap fairing, the impact absorbing extension is a moveablestructure that retracts into the side portion upon impact from thetrailer while providing a physical barrier between the side portion ofthe fairing body and the trailer. Other embodiments use an impactabsorbing extension that is hinged to the side portion and rotates uponimpact from the trailer while maintaining a physical barrier between thefairing body and trailer.

The front portion of the fairing body is situated directly behind thecab and a separation space exists between a front portion of the fairingbody and the cab. The side portions extend rearwardly from the frontportion toward the trailer thereby inhibiting cross-winds from enteringthe gap and assisting in streamlining air flow from sides of the cab tothe trailer. In some embodiments, the top portion is connected to atleast the front portion and extends to the side portions. The topportion is preferably upwardly sloping from the front portion of thefairing body and terminating in a trailing end located behind the sideportions. The side portions can be generally parallel to one another orcan converge toward one another.

The fairing body optionally includes at least one clear section in oneof the side portions, preferably located on a passenger side of thetractor. This clear section is positioned to enable a driver of thetractor to view the trailer from a rear window of the cab when thetrailer is angled with respect to the tractor.

In some embodiments of the gap fairing there is a seal element disposedbetween the cab and the fairing body and adapted to seal the separationspace between said cab and the fairing body at outer peripheral portionsthereof. The seal elements have resiliency and flexibility so as toallow relative motion between the fairing body and the cab.

The present invention may also be characterized as an impact absorbingmember for a tractor-trailer combination comprising a panel structuremoveably or fixedly coupled to a fairing body or a cab of thetractor-trailer combination, the panel structure having a leading edgedisposed proximate to the fairing body or the cab of the tractor-trailercombination and a trailing edge extending readwardly from the fairingbody or the cab towards a trailer. The impact absorbing member isconfigured to provide a barrier between the fairing body or the cab andthe trailer during maneuvering of the tractor-trailer. The impactabsorbing member is further configured to assist in inhibitingcross-winds from entering the gap between the tractor and the trailerand streamline air flow from the tractor to the trailer.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and form a partof the disclosure, are as follows:

FIG. 1 is a side elevational view of a conventional tractor-trailerwithout a gap fairing;

FIG. 2 is a side elevational view of the tractor-trailer incorporating agap fairing incorporating some of the features of the present invention;

FIG. 3 is a perspective view of the tractor-trailer with gap fairing ofFIG. 2;

FIG. 4 is a perspective view of a fairing body in accordance with thepresent invention;

FIG. 5 is a front elevational view of the fairing body shown in FIG. 4;

FIG. 6 is a perspective view of a frame of fairing body in FIGS. 4 and5.

FIG. 7 is a fragmentary, perspective view of the frame shown in FIG. 6with portions broken away to illustrate a method of attachment of thefairing body of the present invention to a chassis of a tractor;

FIGS. 8A and 8B illustrate an alternative embodiment of a fairing bodyof the present invention that incorporates a top portion that can bepivoted;

FIG. 9 is an enlarged perspective view of an alternative embodiment ofthe frame for with portions broken away;

FIG. 10, is a fragmentary top plan view of an alternative embodiment ofa fairing body in accordance with the present invention that isinstalled on the tractor-trailer shown in FIGS. 2 and 3;

FIG. 11, is a fragmentary top plan view of a further alternativeembodiment of a fairing body in accordance with the present inventionthat is installed on the tractor-trailer shown in FIGS. 2 and 3;

FIG. 12 is an enlarged fragmentary view of a sealing element used inconnection with the gap fairing shown in FIGS. 2 and 3 with portionsbroken away to show a cross-section thereof;

FIG. 13 is an enlarged fragmentary view of an alternative embodiment ofa sealing element in accordance an aspect of the present invention withportions broken away to show a cross-section thereof;

FIG. 14 is an enlarged fragmentary view of a further alternativeembodiment of a sealing element in accordance an aspect of the presentinvention with portions broken away to show a cross-section thereof;

FIG. 15 is a rear fragmentary, perspective view of a gap fairing withportions of the tractor and the gap fairing removed to illustrate aclear panel used in enabling a driver to view the trailer on a passengerside of the tractor;

FIG. 16 is a partial side elevational view of the tractor-trailerarrangement incorporating a gap fairing in accordance with the presentinvention;

FIG. 17 is a perspective view of an embodiment of the fairing body andimpact absorbing extensions in accordance with the present invention;

FIG. 18 is a perspective view of another embodiment of the fairing bodyand impact absorbing extensions in accordance with the presentinvention; and

FIG. 19 is a perspective view of yet another embodiment of the fairingbody and impact absorbing extensions in accordance with the presentinvention.

DETAILED DESCRIPTION

With reference to FIG. 1, a conventional tractor-trailer 1 isillustrated that does not include gap fairing in accordance with thepresent invention. Tractor-trailer 1 has a tractor 2 having a cab 10mounted on a chassis 12 which contains the engine for the tractor and acockpit for drivers and passengers. Mounted towards the rear portion ofthe chassis 12 of the tractor 2 is a king-pin pivot 14 which pivotablyconnects the trailer 3 to the tractor 2 to allow the tractor-trailer 1to be maneuvered and turned. The trailer 3 is of the type that mounts acylindrical tank 18 that can be of circular or oval cross-section tocontain liquid products of various types. In addition, the cab 10includes a GPS antenna dome arrangement 20 as well as an auxiliaryhydraulic unit and associated frame 22. An exhaust pipe 24 dischargescombustion gases from the tractor engine in a manner such that the fumesare elevated above normal road vehicles traveling near or behind thetractor-trailer 1.

A substantial gap 26 is formed between the cab 10 and the trailer 3. Asmentioned above, such gap 26 results in aerodynamic drag being impartedto the tractor-trailer 1 when traveling at highway speed fromcross-winds entering the gap. Additionally, there is a geometricmismatch between the rectangular transverse profile of the cab 10 andthe cylindrical or oval tank 18 which also will induce aerodynamic drag.The total of such drag on the tractor-trailer 1 results in a decrease ingas mileage and therefore, an increased cost to the fleet operator.

It is to be noted that although trailer 3 is of the type that mounts acylindrical tank 18; and the invention has been described in connectionwith such a trailer, this is for exemplary purposes only. The presentinvention would have equal application to a tractor-trailerincorporating any type of trailer, for example, a van trailer or a dumptrailer.

With reference to FIGS. 2 and 3, tractor-trailer 1 is illustratedincorporating a gap fairing 4 in accordance with the present invention.Gap fairing 4 includes a fairing body 28 connected to the chassis 12 andpreferably, a gap seal element 29 to seal a separation space 120,illustrated hereinafter in FIGS. 12-14, between the fairing body 28 andthe cab 10. The fairing body 28 is located within the gap 26 to helpinhibit the effect of cross-winds and to provide a degree ofstreamlining that will reduce aerodynamic drag due to geometric mismatchbetween the cab 10 and the tank 18 and a height mismatch due to the factthat the top of front portion 19 of tank 18 is located at a higherelevation than the top of cab 18. Preferably, as will be discussedbelow, the fairing body 28 is designed such that the GPS antenna domearrangement 20 is located within the fairing body 28 and the exhaustpipe 24 extends through fairing body 28 in a unimpeded manner. Openingscould be provided on both sides of the fairing body 28 depending on thetractor exhaust configuration.

With additional reference to FIG. 4, fairing body 28 has a front portionor leading end formed by a front member 50 of a the frame 36 to bediscussed hereinafter that preferably has a cross-sectional size andshape that essentially matches that of the rear portion of the cab 10.Extending rearwardly of the front portion is a top portion 30 and twoopposed side portions 32 and 34 that are formed of panels or othercovering that are supported by the frame 36. With brief reference toFIG. 3, the back of the fairing body 28 is open, which permits visualinspection, access, illumination, minimized weight, and ventilationincluding that required for an auxiliary hydraulic unit 22 and theengine exhaust pipe 24. This being said, embodiments of the presentinvention are possible in which the back of the fairing body 28 ispartially or completely closed for such purposes as stiffening of thefairing body 28, aerodynamic improvement, impeding and/or controllingaccess to the space underneath the fairing body 28. Although notillustrated, the surfaces or trailing end of the fairing body 28 couldbe provided with supplemental aerodynamic features including; vanes,fins, guides, channels, spoilers or other features to further optimizeairflow and minimize aerodynamic drag by providing streamliningcapabilities. Moreover, also as not illustrated, hand holds, steps,tie-offs or other features can be incorporated or added to the fairingbody 28 enhance accessibility or to provide protection of itemstransported on the tractor-trailer.

The top portion 30 has a wedge-like roof section 38 that is upwardlyinclined from the front of the fairing body 28 and a pair of transitionsections 40 and 42 that extend from the wedge-like roof section 38toward the opposed side portions 32 and 34. The panel forming thetransition section 40 is provided with an opening 44 for the exhaustpipe 24 which thereby extends through the firing body 28. The wedge-likeroof section 38 is provided with a window 46 formed of fiberglass orother material that allows for transmission of GPS signals to the GPSantenna 20 that is housed within the fairing body 28 and supported by atray 86 to be discussed. The wedge-like roof section 38 is upwardlyinclined from the roof of the cab 10, at or about the height of the cab10, to a level, at or near the height of the top of the cylindrical tank18. Preferably the inclination of the wedge-like roof section from thehorizontal plane is in a range of at least 5 degrees and preferably nogreater than 30 degrees. It is to be noted that the wedge-like roofsection 38 presents a planar surface to the air flowing from the cab 10to the tank 18 to deflect the air over the top of the tank 18 at a frontportion thereof. Preferably, the wedge-like roof section 38 extendsbehind the side portions 32 and 34. In this regard, the wedge-like roofsection 38 terminates in a trailing edge 39 that is behind the rearedges of side portions 32 and 34. This extension of the wedge-like roofsection allows for a more gradual slope for smooth air flow transitionand greater closure of the gap 24, than would be possible without theextension, while maintaining the gap fairing side clearance allowing forat least a 90 degree articulation during back-up maneuvers of thetractor cab and cylindrical trailer combination. For example, if apossible embodiment of the present invention were made with an upwardlysloping roof section positioned at an intermediate location of the topportion 30 that was sized to deflect air over the tank 18, the slopewould be more abrupt leading to more aerodynamic drag than thewedge-like roof section 38 due to higher profile drag and turbulencewithin the larger open area between the fairing body 28 and the tank 18.

While the wedge-like roof section 38 could incorporate a curvature inits upwardly sloping surface, the use of such a planar section has beenfound by the inventors herein not to significantly increase aerodynamicdrag over such a curved section while at the same time can bemanufactured more easily and less expensively than a curved design.Furthermore, it is important to note that the position of the wedge-likeroof section 38, unlike the prior art, is not provided over the roof thecab, but instead is located behind the cab itself allowing for muchlower costs in constructing the gap fairing 4 of the present invention.Moreover, the installation of the gap fairing 4 is far less expensivethan prior art designs because, as will be discussed, the fairing body28 is simply and more directly attached to the chassis 12.

As can best be seen from FIG. 5, each of the transition sections 40 and42 preferably have a curved transverse configuration that at the frontor leading end of the fairing body 28 has a radius “R1” that is smallerthan the radius at the trailing end of the transition sections “R2” forstreamlining purposes. Preferably, the radius “R1” can be selected tosubstantially match the radius between the roof and sides of the cab 10as shown by “R1”, and the radius “R2” can be selected to substantiallymatch the radius of the tank 18 or similar tanks for a greaterstreamlining effect. Although the transition sections 40 and 42 could beformed of flat plates, the rounded radius configuration is preferredfrom the aspect of reducing aerodynamic drag by providingaerodynamically streamlined contoured sections that transition from thecab 10 to the tank 18. In this regard the top portion 30 couldincorporate a curvature to mimic or approach the shape of thecylindrical tanker trailer. However this would add to the complexity ofthe fairing body 28 and therefore, the expense in manufacturing thesame.

The two opposed side portions 32 and 34 extend from the transitionsections 42 and 40, respectively, toward the bottom of the fairing body28 or when installed, toward the chassis 12. The side surfaces formed bythe side portions 32 and 34 are planar. The side portions 32 and 34extend back as far as practical to minimize the gap 26, but not so faras to interfere with the trailer sides during articulation and backingmaneuvers. During these maneuvers, the angle of articulation may exceed90 degrees. Consideration is given for minimum clearances duringcombination of articulation and traverse of road irregularities whichalso affect the relative location of the tanker trailer and the fairingbody 28.

The design of the side portions 32 and 34 of the fairing body 28 canalso be extended with resilient materials to accommodate contact withthe tanker trailer during extreme articulation angles, yet provide theincreased benefit of more complete gap elimination. The materials usedfor extension of the side portions or side panels can be elastomeric andflexible, bristles of a tightly formed brush, hinged rigid, orsemi-rigid subsections. Portions or all of the side panels can be madeoptically transparent to reduce the visibility reduction associated withthe gap fairing such as a clear side pane 150 incorporated into a sideportion 32 as shown in FIG. 15 and as will be discussed in more detail,hereinafter. The side panels can either end at a level above the cabbottom or below the cab bottom. Any of the surfaces of the gap fairingcan be equipped with fixed or actuated openings to dissipate airpressure from a gap fairing-equipped tractor being towed backwards.

The panels forming wedge-like roof section 38, the transition sections40 and 42 and the side portions 32 and 34 are preferably formed fromaluminum. Aluminum sheet formation is particularly advantageous for thetransition sections 40 and 42 because such sections preferablyincorporate a curvature and the formability of aluminum, or plasticalternatives, allows for smooth transition between this relatively smallradius on the leading edge of the transition sections 40 and 42 and thelarger radius at the rear of the transition sections 40 and 42. Theinherent stability and stiffness of such curved sheets minimizes theneed for additional structure, minimizing weight and cost. Othermaterials of construction could of course be used such as fiberglass orother fiber reinforced polymeric materials and thermoplastics and/orthermoplastic elastomers or other elastomers. In place of panelsattached to a frame, the entire fairing body 28 could be integrallyformed with an outer covering to provide the desired shape and strength,as with ribs or contoured sections to provide the structuralcontribution. Alternatively, in place of panel construction, flexiblematerials such as high performance fabric stretched taught over aframework are possible.

With reference to FIG. 6, the frame 36 preferably incorporates membersthat are connected in the illustrated space frame that are each formedby aluminum rectangular tubing. Frame 36 is provided with a front member50 that is shaped into an inverted “U”-like configuration. Support forthe panels forming the side portions 32 and 34 is provided by topmembers 54 that are angled upwardly with respect to bottom members 52that are in turn connected, at opposite ends, to the front member 50 andrear members 56. Intermediate members 58 are connected at opposite endsto front member 50 and rear members 56. The panel forming the wedge-likeroof section 38 is framed by two parallel members 60 and 62 that areconnected to the front member 50. An end member 64 and an intermediatemember 66 are connected at opposite ends to the two parallel members 60and 62. The panels forming the transition sections 42 and 40 aresupported by side members 54, top members 60 and 62, and front member 50Further structural integrity is provided for the wedge-like roof section38 by vertical members 72 that are connected at their top ends tointermediate member 66 and at the bottom by bottom cross-members 74 and76. Further structural integrity is provided by angled structuralmembers 68 and 70, connecting the wedge-like roof section structure toside members 54. Further strength is provided by pairs of intermediatecross members 78 and 80 that are connected at opposite ends to verticalmembers 72 and intermediate members 58. Brace-like members 82 areconnected at opposite ends to bottom cross-members 74 and 76 and bottommembers 52 and intermediate brace-like members 84 are connected tointermediate members 58 and intermediate cross members 78 and 80. A GPSsupport tray 86 is situated beneath window 46 to support the GPS antenna20. Support tray 86 is in turn connected to front member 50 andintermediate member 66.

As could be appreciated by those skilled in the art, the constructionemployed in fabricating the fairing body 28 and its frame 36 areconventional. For instance, the members, discussed above and making upthe frame 36 can be attached by welding. The panels covering the frame36 and forming the top portion 30 and the side portions 32 and 34 can beattached to the frame 36 by such means as pop rivets. Other possiblefastening means include adhesive bonding, polymeric welding by heat orsolvent, threaded fasteners, hook-and-loop fasteners and interlockingconfigurations.

The fairing body 28 is attached to the chassis 12 by attaching the frame36 to the chassis 12 by such means as welding, clamping, bolting,pinning or other structurally adequate attachment means. As illustrated,in FIG. 7, such attachment to the chassis is effectuated by means ofangle-like brackets 89 that are bolted to vertical members 72 and to therear portion or frame of the auxiliary hydraulic unit 22 which is inturn connected to the chassis 22. In this fashion, the gap fairing 26 isable to be incorporated into an OEM tractor manufacturer's cab shape andother design features. It is possible to attach frame 36 to the chassis12 using brackets. These brackets can be structurally shaped platematerial clamping the frame 36 to the chassis 12 or other pre-existingstructural features on the tractor.

With reference to FIGS. 8A and 8B, a fairing body 28′ is illustratedthat incorporates a top portion 30′ and other structural modificationsto the frame 36, discussed above, that is designed to allow a degree ofadjustment in the fairing body 28′ to enable use of such fairing bodywith trailers and therefore, tanks 18′ of differing height relative tothe chassis 12 or size. To such end, the top portion 30′ is capable ofpivoting motion and is provided with modified transition sections suchas 42′ that compared to transition section 42 discussed above has agreater height “H”. The transition section opposite to transitionsection 42′ incorporates a similar modification to the transitionsection 40 discussed above. Both of such modified transition sectionsare also wider than the transition sections 42 and 40 and are providedwith a lower edge 90. The side portions, such as the side portion 34′are identical to the side portion 34 or side portion 32 for that matterand the top edge 92 thereof is at the same spacing from the bottom edge94. This being said, for reasons that will become apparent the spacingbetween top and bottom edges 92 and 94 could incorporate a differentspacing from those of side portions 32 and 34. With reference to FIG.8A, the top portion 30′ is at its uppermost position level with the tank18. However, where a tank 18′ is used that is at a lower height thantank 18 the top portion 30′ can be pivoted to accommodate such height.With reference to FIG. 8B, in order to accommodate this lower height,the top portion 30′ is pivoted downwardly in the direction “A” and thelower edge 90 of the transition section 42′ can be seen to be below thetop edge 92 of the side portion 34′ which is now enclosed by thetransition section 42′ due to the overlap.

With additional reference to FIG. 9, a modified version of the frame 36is illustrated as frame 36′ to enable the pivoting motion of the topportion 30′. One such modification is to the front member 50 describedabove by providing a front member 50′ that is split at the legs of its“U” like configuration to form an upper “U” like portion 96 and twolower leg portions 98 which are connected by means of a hinge 100. Theupper member 54′ of the modified frame, that would be coincident withthe lower edge 90 of the transition section 42′, is connected, at oneend to the resulting upper “U” like portion 96 of the front member 50′.Upper member 54′ would in other respects be identical to the uppermember 54 described above. This hinge 100 allows for the pivoting motionof the modified top portion 30′. In order to allow such motion whilestill providing support, frame 36′ is also provided of vertical members72′ that are a modification of the vertical members 72, discussed above.Vertical members 72′ are telescopic and are provided with a top section102 telescoped within a bottom section 104. The top and bottom sections102 and 104 are also provided with a series of holes 106 through which abolt or pin can be positioned to lock the top and bottom sections 102and 104 in place. The top section 102 is connected to the intermediatemember 66 by a pivotable connection 108. The bottom section 104 isconnected to the lower portion of vertical members 72′ by means of apivotable connection 109. Additionally, a further modificationincorporated into the frame 36′ is to similarly split rear member 56′,above intermediate member 58 into a top section 110 telescoped within abottom section 112. Top and bottom sections 110 and 112 are providedwith a series of holes 114 through which a bolt or pin can be extendedto lock the sections in place. Top Section 112 is connected to endmember 70 by a pivotable connection 116. The bottom section 112 isconnected to the remainder of split rear member 56′ by means of apivotable connection 117. The frame 36′ is otherwise similar to frame36.

A yet further modification to a fairing body in accordance with thepresent invention is shown in FIG. 10 in which a fairing body 28″ isprovided in which modified side portions 32″ and 34″ are provided thatconverge towards a tank 18″ of smaller diameter than the tank 18discussed above and mounted on a trailer 3″. The top portion 30″ is alsomodified with a tapered wedge-like roof section 38″ and modifiedtransition sections 40″ and 42″ that are narrower than the transitionsections 40 and 42 and that extend downwardly from tapered wedge-likeroof section 38″ to the side portions 32″ and 34″. A yet furthermodification to the fairing body is shown in FIG. 11 to accommodate thesmaller diameter tank 18″ in which a fairing body 28′″ is provided withside portions that have two substantially parallel side sections 32A and34A and two converging end sections 32B and 34B that converge toward thetank 18″. The top portion 30′″ is modified by providing a set of twotransition sections 40A and 420A that extend from the wedge-like roofsection 38″ (of the same design as that used in the embodiment shown inFIG. 10) toward the substantially parallel side sections 32A and 34A andanother set of two transition sections 40B and 420B that extend towardthe converging end sections 32B and 34B, respectively. As could beappreciated, the frame supporting such fairing bodies 28″ and 28′″ wouldbe a modification of the frame 36, discussed above, in a manner known inthe art.

As mentioned above, the independent mounting of the fairing body 28 tothe chassis 12 rather than the cab 10 is important in that the cab ismounted by a suspension that will isolate the cab 10 from vibration.This leaves a slight separation space 120 between the rear of the cab 10and the front of the fairing body 28. The seal element 29 has been foundby the inventors herein not only to reduce drag as a result of theseparation space 120, but also, to reduce noise due to air turbulencethat would otherwise be induced by such separation space 120. In orderto prevent the transmission of relative motion between the cap 10 andthe fairing body 28, the seal element 29 is at least in part flexible orresilient or both flexible and resilient so that such seal element 29will fill in or cover the separation space 120 but will not transmitforces due to the relative motion. With reference to FIG. 12, sealelement 29 is designed to cover the separation space 120 and includes arigid strip-like element 122, formed of metal or a stiff composite,which extends around a rear peripheral portion 124 of the cab 10. Therigid strip-like element 122 is attached by rivets 126 or other suitableattachment means to the cab 10 such that the rigid strip-like element122 extends from the cab 10 towards the fairing body 28. The resilientor flexible part of the seal element 29 is provided by a flexiblestrip-like element 128 that is attached to the rigid strip-like element122 also by rivets 130 that pass through the rigid strip-like element122 and the flexible strip-like element 128 and are anchored in place byindividual anchoring plates 131. The flexible strip-like element 128simply rests upon or overlaps the front periphery 132 of the fairingbody 28. As illustrated, the cab 10 is slightly higher than the frontportion 132 of the fairing body 28 that is situated at the front member50. The overlap of the flexible strip-like element 128 of the gap sealelement accommodates a variable space between the cab 10 and the fairingbody 28, allowing less precise positioning of the fairing body 28 on thetractor chassis 12.

With reference to FIG. 13, an alternative embodiment of the seal element29 is illustrated as seal element 29′. Seal element 29′ is itself aresilient element in the form of a cushion-like element 134 that islocated within the separation space 120 and is configured to extendaround a rear peripheral portion of the cab 10 and a front portion ofthe fairing body. In this regard, the cushion-like element 134 has afront surface 136 that is shaped to conform with the rear peripheralportion 138 of the cab 10 and which as illustrated incorporates a slightcurvature. An opposite surface 140 of the cushion-like element 134 isshaped to conform to and contact the front portion 132 of the fairingbody 28. The cushion-like member can be formed by an elastomer that maybe a molded, extruded, or otherwise solid, cellular, foamed, foamed witha solid skin, or hollow fitted section. The cushion-like element 134 canbe attached to the rear peripheral portion of the cab 10 by means of alayer of glue or adhesive 141. The cushion-like element 134 may be amolded, extruded, or otherwise a solid, cellular, foamed, foamed with asolid skin, or hollow fitted section. Although not illustrated, thecushion-like element 134 can be attached to the fairing body 28.

With reference to FIG. 14, a yet further alternative embodiment of thesealing element is illustrated an designated by reference number 29″.Sealing element 29″ is preferably a rubber extrusion or other extrudedmaterial that is both flexible and resilient. As illustrated, it has a“V”-like transverse cross-section having two leg-like sections 142 and144. Leg-like section 142 is attached to a rear of the peripheralportions of the cab 10 at the peripheral surface 138 thereof by a layerof glue or adhesive 145. Given the flexibility of the leg section 142,it conforms to such peripheral surface 138. The other leg-like section144 rests upon a front of the peripheral portions of the fairing body 28situated at the front portion 132 thereof and covering the separationspace 120 and enclosing the leg section 142.

With additional reference to FIG. 15, in any embodiment of the presentinvention a clear panel 150 can be provided within the side portion 32situated on the passenger side of the tractor as viewed with the gapfairing 4 is installed. It is to be noted that the term, “passengerside” means the side of the tractor that is opposite to which the driversits and operates the tractor. For instance, in those countries in whichtraffic proceeds along the right side of a highway, as viewed by thedriver, the driver will sit on the left side of the vehicle and thepassenger side will be located right side, also as viewed by the driver.The reverse would be the case in other countries in which trafficproceeds along the left side of the highway. The clear panel 150 ispositioned to enable the driver to view the trailer 3 from the rearwindows 152 and 154 thereof when the trailer 3 is angled towards thepassenger side. As can be appreciated, when the trailer is angledtowards the driver side, the driver can position him or herselfpartially out the side window of the tractor 2 to view the trailer 3.However, if the side portion of the fairing 4 were not provided with theclear panel 150, forming at least a section of the side portion 34 ofthe fairing 4, while the driver would be able to see the trailer 3 outof the side view mirror 156, the driver would not be able to see theexact position of the trailer 3. This ability to inspect the position ofthe trailer 3, is particularly advantageous in driving operations inwhich the tractor trailer 1 is being backed up around a curve or into aloading area.

As can be appreciated, the other side portion 34 could be provided withthe clear panel 150 for the sake of consistency. Also, the entire sideportion 32 and, optionally side portion 34, could be made of a clearmaterial as indicated above. Lastly, although the use of the clear panel150 is particularly advantageous in a gap fairing, such as gap fairing 4in accordance with the present invention that is attached solely to thechassis of the tractor and independent of the cab 10, the use of such aclear panel or the like could be used in connection with any gapfairing, even a fairing of the prior art that is attached to a cab of atractor trailer and overlies the roof of the cap or one that is a gapfairing but does not incorporate an upwardly sloping top portion.

With reference to FIGS. 16 and 17, the embodiments of the presentinvention include impact absorbing extensions 170 extending rearwardlyfrom the side portions 32, 34. These impact absorbing extensions 170 areconfigured to protect the fairing body 28 from any impact by the trailerduring maneuvering of the tractor-trailer.

The impact absorbing extensions 170 may be separately attached to thedistal end of the side portions 32, 34 on each side of thetractor-trailer or can be manufactured as an integrated section of theside portions 32, 34 of the fairing body 30. The impact absorbingextensions 170 are preferably constructed of flexible, compressible orresilient type materials to provide a cushion-like barrier between thefairing body 30 and the sides of the trailer during maneuvering of thetractor-trailer.

FIGS. 18 and 19 depict alternate embodiments of the present inventionwith the impact absorbing extensions 170 extending rearwardly from theside portions 32, 34. In these embodiments, the impact absorbingextensions 170 are moveable structures that protect the fairing body 28from any impact by the trailer during maneuvering of thetractor-trailer. In FIG. 18, the impact absorbing extensions 170 retractinto the fairing body 28 when impacted thereby absorbing the force ofthe impact without damage to the fairing body 28. In FIG. 19, the impactabsorbing extensions 170 are connected to the distal end of the sideportions 32, 34 of the fairing body 30 with hinges that allow the impactabsorbing extensions 170 to rotate when impacted by the trailer therebypreventing structural damage to the fairing body 28.

In the illustrated embodiments, the impact absorbing extensions 170 arepreferably constructed of an elastomeric material disposed along theentire distal end of the side portions 32, 34 of the fairing body 30.The dimensions of the impact absorbing extensions 170 are selected toprovide additional drag reduction benefits and airflow streamliningbenefits associated with of the gap fairing while preventing any impactbetween the trailer and the fairing body during articulating maneuversof the tractor-trailer.

While particular embodiments have been described and or illustrated,such are not intended to be limiting. Modifications and changes maybecome apparent to those skilled in the art, and it is intended that theinvention be limited only by the scope of the appended claims.

We claim:
 1. A gap fairing for reducing aerodynamic drag of atractor-trailer having a tractor and a trailer pivotably connected tothe tractor, said gap fairing comprising: a fairing body attached to achassis of the tractor within a gap between a cab of the tractor and thetrailer of said tractor-trailer and configured to enable the trailer topivot during maneuvering of the tractor-trailer, the fairing body havinga front portion situated directly behind the cab, side-portionsconnected to the front portion and extending rearwardly toward thetrailer, and a top portion extending to the side portions; and one ormore impact absorbing extensions extending rearwardly from fairing bodyand configured to protect the fairing body and the trailer from anyimpact between the fairing body and the trailer during maneuvering ofthe tractor-trailer; wherein the impact absorbing extensions and theside portions are configured to inhibit cross-winds from entering thegap and streamline air flow from sides of the cab to the trailer.
 2. Thegap fairing of claim 1 wherein a separation space exists between thefront portion of the fairing body and the cab.
 3. The gap fairing ofclaim 1 wherein the impact absorbing extension is a flexible,compressible or resilient type material that provides a barrier betweenthe side portion of the fairing body and the trailer.
 4. The gap fairingof claim 1 wherein the impact absorbing extension is formed of anelastomeric material.
 5. The gap fairing of claim 1 wherein the impactabsorbing extension is a moveable structure that retracts into the sideportion upon impact from the trailer while providing a physical barrierbetween the side portion of the fairing body and the trailer.
 6. The gapfairing of claim 1 wherein the impact absorbing extension is hinged tothe side portion of the fairing body and is configured to rotate uponimpact from the trailer while providing a physical barrier between theside portion of the fairing body and the trailer.
 7. The gap fairing ofclaim 1 wherein the top portion is connected to at least the frontportion and extends to the side portions, and wherein the top portionextends from the front portion of the fairing body and terminates in atrailing end located behind the side portions.
 8. The gap fairing ofclaim 1 further comprising at least one clear section on at least one ofthe side portions and positioned to enable a person in the cab to viewthe trailer from a rear window of the cab when the trailer is angled. 9.The gap fairing of claim 8 wherein the at least one clear section islocated on a passenger side of the tractor.
 10. The gap fairing of claim1 further comprising a seal element configured to seal the separationspace between said cab and the fairing body at outer peripheral portionsthereof and at least in part having at least one of a resiliency and aflexibility so as to allow relative motion between said fairing body andsaid cab.
 11. The gap fairing of claim 1 wherein the side portions areparallel to one another.
 12. The gap fairing of claim 1 wherein at leastpart of the side portions converge toward one another or diverge awayfrom one another.
 13. An impact absorbing member for a tractor-trailercombination comprising: a panel structure moveably or fixedly coupled toa fairing body or a cab of the tractor-trailer combination, the panelstructure having a leading edge disposed proximate to the fairing bodyor the cab of the tractor-trailer combination and a trailing edgeextending readwardly from the fairing body or the cab towards a trailer;wherein the impact absorbing member is configured to provide a barrierbetween the fairing body or the cab and the trailer during maneuveringof the tractor-trailer; and wherein the impact absorbing member isfurther configured to assist in inhibiting cross-winds from entering thegap between the tractor and the trailer and streamline air flow from thetractor to the trailer.
 14. The impact absorbing member of claim 13wherein the trailing edge of the panel structure is a flexible,compressible or resilient type material that prevents direct impactbetween the fairing body or the cab and the trailer.
 15. The impactabsorbing member of claim 14 wherein the panel structure is fixedlycoupled to the fairing body or the cab of the tractor-trailercombination.
 16. The impact absorbing member of claim 13 wherein all ora portion of the trailing edge of the impact absorbing member is formedof an elastomeric material.
 17. The impact absorbing member of claim 13wherein the panel structure is moveably coupled to the fairing body orthe cab of the tractor-trailer combination and the panel structureretracts towards the cab upon impact with the trailer.
 18. The impactabsorbing member of claim 13 wherein the panel structure is moveablycoupled to the fairing body or the cab of the tractor-trailercombination and the panel structure is hinged to the fairing body or thecab and is configured to rotate towards the cab upon impact with thetrailer.